Plate freezers, in particular vertical plate freezers are commonly used to freeze food (for human or animal consumption). A vertical plate freezer consists of a number of parallel plates, mounted vertically, through which a refrigerant runs. The plates are positioned interdistantly to leave a row of multiple freezing compartments, also called “pockets”, between the plates. The product is simply poured into the pockets between the plates and will be frozen as blocks. A plate freezer enables rapid freezing of raw food products through its direct contact method of freezing, which offers a significant energy saving and reduced freezing time. These costs savings are also benefitted by the fact the product is poured directly into the freezer, not requiring expensive packaging material which can increase freezing time and is liable to get damaged during use. Semi-automated loading and unloading systems allow a high product throughput for very low labour costs. Various types of plate freezers are described in EP 2273220 A2.
Loading typically takes place by (automatically) guiding a flexible tube to the upper (open) side of the plate freezer. Through this tube liquid food material is pumped into the pockets of the freezer. Unloading typically takes place by lifting the frozen blocks out of the pockets. Thereafter, filling plates (also called fitting panels) are manually positioned in between the blocks and the complete row is clamped by pressing the proximal and distal end of the row of block with filling plates to each other using a large clamp. This way, the blocks can be transported to another location. Alternatively, no filling plates are positioned between the blocks. In this case the blocks are firstly, very gently, moved until they are contiguous. Thereafter the row of blocks can be grasped at the proximal and distal end. This method however is very time consuming and prone to faults due to falling block (the “Domino Effect”). A more expensive system to unload the freezer is to release the blocks to a belt underneath the freezer, whereafter the blocks are transported by moving the belt, optionally after filling plates have been positioned in between the blocks to try and prevent the Domino Effect.